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Fundamental properties of Kepler and CoRoT targets - III. Tuning scaling relations using the first adiabatic exponent.

Authors :
Yıldız, M.
Orhan, Z. Çelik
Kayhan, C.
Source :
Monthly Notices of the Royal Astronomical Society; 10/21/2016, Vol. 462 Issue 2, p1577-1590, 14p
Publication Year :
2016

Abstract

So-called scaling relations based on oscillation frequencies have the potential to reveal the mass and radius of solar-like oscillating stars. In the derivation of these relations, it is assumed that the first adiabatic exponent at the surface (Γ<subscript>1s</subscript>) of such stars is constant. However, by constructing interior models for the mass range 0.8-1.6 M<subscript>⊙</subscript>, we show that 1s is not constant at stellar surfaces for the effective temperature range with which we deal. Furthermore, the well-known relation between large separation and mean density also depends on Γ<subscript>1s</subscript>. Such knowledge is the basis for our aim of modifying the scaling relations. There are significant differences between masses and radii found from modified and conventional scaling relations. However, a comparison of predictions of these relations with the non-asteroseismic observations of Procyon A reveals that new scaling relations are effective in determining the mass and radius of stars. In the present study, solar-like oscillation frequencies of 89 target stars (mostly Kepler and CoRoT) were analysed. As well as two new reference frequencies (ν<subscript>min1</subscript> and ν<subscript>min2</subscript>) found in the spacing of solar-like oscillation frequencies of stellar interior models, we also take into account ν<subscript>min0</subscript>. In addition to the frequency of maximum amplitude, these frequencies have a very strong diagnostic potential in the determination of fundamental properties. The present study applies the derived relations from the models to the solar-like oscillating stars, and computes their effective temperatures using purely asteroseismic methods. There are in general very close agreements between effective temperatures from asteroseismic and nonasteroseismic (spectral and photometric) methods. For the Sun and Procyon A, for example, the agreement is almost total. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00358711
Volume :
462
Issue :
2
Database :
Complementary Index
Journal :
Monthly Notices of the Royal Astronomical Society
Publication Type :
Academic Journal
Accession number :
117972408
Full Text :
https://doi.org/10.1093/mnras/stw1709